The invention relates to a transponder which has at least one signal channel, which signal channel has transmission means and at least two signal processing stages connected to the output side of said transmission means.
The invention further relates to an integrated circuit for a transponder, which integrated circuit has at least one signal channel, which signal channel has transmission means and at least two signal processing stages connected to the output side of the transmission means.
A transponder as described above and an integrated circuit as described above have been developed and marketed in various embodiments by the Applicant and are therefore known. In the known embodiments, the transponder or the integrated circuit of the transponder has a fixed circuit configuration, so that the signal processing stages provided must be permanently supplied with power in their totality by power supply means of the transponder, i.e. by means of a non-rechargeable battery, with the consequence that all signal processing stages are permanently supplied with power in all possible operating conditions with the known embodiments, which in some operating conditions results in unnecessarily high energy consumption. This is particularly disadvantageous if the power supply of the transponder or of its integrated circuit is effected by means of a non-rechargeable battery, because the service life of the non-rechargeable battery is detrimentally influenced, i.e. shortened, by unnecessarily high energy consumption.
It is an object of the invention to eliminate the above difficulties and to realize an improved transponder and an improved integrated circuit.
To achieve the above-mentioned object, inventive features are provided in a transponder according to the invention such that a transponder according to the invention can be characterized in the following manner:
A transponder having at least one signal channel, which signal channel having transmission means and at least two signal processing stages connected to the output side of the transmission means, wherein at least one signal processing stage is configured so as to be activatable and deactivatable, and wherein for each activatable and deactivatable signal processing stage an associated bypass branch being provided for bypassing the associated signal processing stage, which bypass branch is also configured so as to be activatable and deactivatable, and wherein control means are provided by which the at least one activatable and deactivatable signal processing stage and the at least one associated activatable and deactivatable bypass branch are activatable and deactivatable, and wherein the control means and the at least one activatable and deactivatable signal processing stage and the at least one associated activatable and deactivatable bypass branch are configured such that upon deactivation of an activatable and deactivatable signal processing stage activation of the bypass branch associated with this signal processing stage occurs at the same time, and that upon activation of a signal processing stage deactivation of the bypass branch associated with this signal processing stage occurs at the same time.
To achieve the above-mentioned object, inventive features are provided in an integrated circuit according to the invention such that an integrated circuit according to the invention can be characterized in the following manner:
An integrated circuit for a transponder, which integrated circuit having at least one signal channel, which signal channel having transmission means and at least two signal processing stages connected to the output side of the transmission means, wherein at least one signal processing stage is configured so as to be activatable and deactivatable and wherein for each activatable and deactivatable signal processing stage for bypassing the associated signal processing stage, which bypass branch is also configured so as to be activatable and deactivatable, and wherein control means are provided by which the at least one activatable and deactivatable signal processing stage and the at least one associated activatable and deactivatable bypass branch are activatable and deactivatable, and wherein the control means and the at least one activatable and deactivatable signal processing stage and the at least one associated activatable and deactivatable bypass branch are configured such that upon deactivation of an activatable and deactivatable signal processing stage activation of the bypass branch associated with this signal processing stage occurs at the same time, and that upon activation of a signal processing stage deactivation of the bypass branch associated with this signal processing stage occurs at the same time.
The provision of the features according to the invention create the possibility in a relatively simple manner, in particular with the use of integrated technology and without substantial additional cost, that of all the activatable and deactivatable signal processing stages only those signal processing stages are activated and therefore made into energy consumers which are required for the presently obtaining operating condition from among all operating conditions realizable with the transponder according to the invention and with the integrated circuit according to the invention,. It is achieved thereby that signal processing stages not required for an operating condition remain or become deactivated, so that the deactivated signal processing stages consume no energy, whereby reduced energy consumption is or can be ensured, which is advantageous with regard to the lowest possible energy requirement. The desire to make do with the lowest possible energy requirement is present both in the case of so-called passive transponders, in which energy is supplied by means of a signal transmitted in a contactless manner to the transponder and rectified by means of rectification means, and in the case of so-called active transponders, in which energy is supplied from a non-rechargeable battery.
The activation and deactivation of signal processing stages and bypass branches of a transponder according to the invention or of an integrated circuit according to the invention can be realized, for example, during manufacture of the integrated circuit or the transponder, such that, subject to the executed activation and deactivation of the signal processing stages and bypass branches, a fixed circuit configuration is provided after manufacture. However, it has also proved advantageous if the activation and deactivation of signal processing stages and bypass branches can carried out in a programmable manner, it being possible to carry out such programmable activation and deactivation, for example, in that a communication station provided to communicate with the transponder according to the invention sends a command to this transponder, which command is evaluated in the transponder, and in consequence an activation or deactivation of signal processing stages and of bypass branches is effected, and therefore a change of the signal configuration.
In a transponder according to the invention or an integrated circuit according to the invention, the signal processing stages can be formed by filter stages or by decoding stages or by signal-generating stages. However, the measures according to the invention have proved particularly advantageous if at least some of the activatable and deactivatable signal processing stages are formed by amplifier stages. In this connection it may be mentioned that it is advantageous, for example, in a transponder with a large-area transmission coil in the transmission means, and therefore a high reception sensitivity, to deactivate one on more amplifier stages, since in this case it is possible to make do with a small number of amplifier stages, i.e. with at least one amplifier stage, it thereby being possible to make do with a low energy consumption because of the small number of amplifier stages to be supplied with energy. It may also be mentioned in this connection that in a transponder according to the invention, in which a small working distance is sufficient so that the transponder is always operated at only a short distance from a communication station and consequently, because of the short distance, receives a relatively high input signal, it is advantageous to deactivate one or more amplifier stages in order to keep the energy consumption in the transponder as small as possible. In this connection it should also be mentioned that at least one amplifier stage may also be deactivated as a function of the amplitude of a signal received with a transponder according to the invention because, for example in the case of a received signal of high amplitude, at least one amplifier stage can be deactivated, since multiple amplification is unnecessary in case of a received signal which in any case has high amplitude.
It has proved particularly advantageous if the features as claimed in claims 3 and 4 and as claimed in claims 7 and 8 are provided in a transponder according to the invention and in an integrated circuit according to the invention. These configurations have proved particularly advantageous with regard to achieving the highest possible diversity in the possible ways of influencing the activation and deactivation of signal processing stages and of bypass branches. The provision of timing means in a transponder according to the invention or an integrated circuit according to the invention offers the advantage, among others, that such additional timing means render it possible in a simple manner to detect the fact that, for a preset time period, for example a period of several days, no use of the transponder or of the integrated circuit has occurred, and that the transponder or the integrated circuit may then be controlled by deactivating all signal processing stages, so as to enter practically a standby state in which only very low energy consumption takes place. A transponder according to the invention or an integrated circuit according to the invention may be switched from such a wait state, for example, by actuating a separate wake-up key provided for this purpose. If the transponder according to the invention is essentially a so-called active transponder, the waking-up of such an active transponder from its standby state may be effected, for example, in that this active transponder is combined with a so-called passive transponder and a wake-up signal is fed in a contactless manner to the passive transponder so as to wake up the active transponder.
The above-mentioned aspects and further aspects of the invention will become apparent from the embodiment described below and are explained with reference to this embodiment.